Deprecation: #92494 - Extbase EnvironmentService

See Issue #92494

Description

The extbase class TYPO3\CMS\Extbase\Service\EnvironmentService is an API for TYPO3’s legacy constant TYPO3_MODE. That constant has been deprecated in v11 and superseded by core API class TYPO3\CMS\Core\Http\ApplicationType which relies on a PSR-7 request to determine frontend or backend mode. The EnvironmentService has now been deprecated as a logical follow-up to these works.

Impact

Using the class will raise a PHP deprecation log level entry and the class will be removed in v12. The class has been marked @internal a while ago already.

Affected Installations

Even though EnvironmentService is @internal, some extensions may still rely on it. The extension scanner will find usages.

Migration

Instances with extensions using that class should either make their code agnostic to frontend or backend mode, or use ApplicationType. Code examples can be found in the Changelog file.